Anita Brookner, who is 80, came late to writing. She was 53, a teacher at the Courtauld Institute with a distinguished academic career, when she published her first book, in 1981, the aptly titled A Start in Life. Three years later she was awarded the Booker Prize for her novel Hotel du Lac. For a long time afterwards Brookner produced a novel a year with clockwork regularity – the first glimmer of summer, a new Brookner – the fruits of what she wrily calls 'displacement activity'. But in recent years her productivity has slowed.

Her new novel, Strangers, is the first in four years. Friends, lunch companions, see less of her. There is the unspoken sense that she is withdrawing. Brookner, who once described her ambition as 'to be unnoticed', rarely gives interviews – has not given one, as far as I can tell, for some 12 years. Everything I had heard about her made her sound formidable. An old acquaintance talked about her intense privacy, and her 'fierce intelligence'.

Her habit of abbreviating social engagements is legendary. Appearances at parties were always described as 'fleeting'. Someone who lunched with her from time to time reported that no matter how early they arrived Brookner would be waiting. Lunch would be short. Brookner lives in a mansion block in Kensington; a milieu that is familiar from many of her novels. I was told to present myself at 2.30 'promptly', and after circling the block twice, rang the doorbell at 2.25. There was no answer, nor from her telephone. I waited, unsure what to do. At length, the door cracked open, and Brookner appeared, small, fragile and watchful. How long, I asked, as we ascended in the lift to the first floor, have you lived here? She sighed. 'Too long.'

Brookner lives alone. She has never married, and the preponderance of disappointed spinsters in her books has inevitably tended to give rise to the assumption that she is that person. 'I feel I could get into The Guinness Book of Records as the world's loneliest, most miserable woman,' she remarked in the year she won the Booker. It is only when you meet her that you can hear the dry, amused, worldly tone that must have informed that sentence as she said it. Her rooms have an elegant, almost austere simplicity. A sofa, an armchair, a coffee table.

Along one wall stands a row of bookshelves, lined with well-thumbed volumes of Sartre, de Beauvoir, Proust, a biography of Henry James. Eighteenth-century prints hang on the pale walls. There is an antique television set on spindly legs that looks as if it might pre-date the introduction of colour, never mind digital. There is no sign of any personal imprimatur – photographs, nostalgic bric-a-brac. The abiding impression is of stillness, silence and serious-mindedness. You sense the absence of visitors. She offers coffee from a cafetiere, and seats herself on the sofa: immaculately dressed; perfectly contained in her movements, a woman of impeccable manners and propriety. 'You will find yourself babbling,' Julian Barnes, an old friend of Brookner's, cautioned me before I met her. 'One of the most remarkable things about her is that her conversation has perfect punctuation, so that you hear every colon and semi-colon; and this makes you aware that your own grammar in spoken English is very sloppy. It's not a deliberate trick to make you feel uneasy; it's simply how she is.'

And Barnes is right. Brookner answers questions with the utmost precision and, often, the utmost brevity, with nothing more than a word or sentence or two. In her bearing, her manner and her conversation there is nothing about her that is superfluous. The morning's newspapers have brought the news of the death of the American novelist John Updike. 'I read everything,' she says. 'And I liked him very much. But now, reviewing the situation, I think I prefer the short stories to the novels. The Complete Henry Bech I re-read over and over. I get the sense he was a good-hearted man. Completely unbiased. That's the difference between American and English fiction, I think. In English fiction there's always a slight sneer somewhere in the background.'

Who are your favourite authors?

"Charles Dickens, first and foremost. My father gave me every volume of Dickens, one for Christmas, one for my birthday, until I'd read the lot. I think young people love Dickens. The funny names, to begin with, and the sense of right and wrong. " And then I think we leap to the French. "And it's to be Flaubert, obviously. Simenon. You haven't read him? Oh, you should. You'd love it. It's short, workmanlike fiction. He brings it off every time. Henry James. And Proust, of course. With Henry James it's the tentativeness. It's all about betrayal, tiny incidents of bad faith, and that's a very intriguing proposition, and inexhaustible. Proust? Well, it's the inwardness that I like, and the impassive gaze, really. I love that." Have either been an influence on you? "No." Has anybody? "I don't think so."

Brookner's new novel tells the story of Paul Sturgis, 73 years of age, a retired banker whiling away his remaining days in a Kensington flat (which seems very like Brookner's own). Bereft of companionship, his sole moorings to society are his encounters with strangers, and his regular visits to a distant cousin, Helena, in Hampstead – for an hour or two's excruciating exchange of pleasantries before each can bid the other a relieved goodbye. Fearful of encroaching infirmity and the prospect of a lonely death, he suddenly, and unexpectedly finds himself drawn into two very different relationships – one with a former girlfriend, another with a younger woman whom he encounters by chance on an excursion to Venice. Sturgis is faced with a choice, whether to invest his future in either woman, or to go on alone.

Anita Brookner in 1990Credit:
Rex Features

The themes are familiar ones: the cruel imbalance of need and desire that underlie relationships, the hopes and the misunderstandings, the yearning for a time of possibilities and for 'true innocence' – that 'brief moment before the onset of disappointment'.

It is, as her books always are, a brilliant forensic examination of the interior life, in all its self-deceptions, hard truths and glimmers of false hopes; a brilliant examination too of solitude and the various strategies employed to stave off ennui, 'the slight failure of nerve' at the gathering darkness. "I wanted to describe a life without work, which is a great problem, as a lot of people are finding out now," Brookner says. "Life without a context, which is a writer's life, is very unpleasant. I wanted to explore what you do not with a blank page, but with a blank day." Tellingly, she chooses as her epigraph a quote from Freud – a lifelong hero – "For all its glory England is a land for rich and healthy people. Also they should not be too old." And this, as the conversation will reveal, is a sentiment that Brookner would now apply to herself.

She was born and brought up in a large Victorian villa in Herne Hill in south London. Her maternal grandfather had emigrated from Poland to Britain, and founded a tobacco factory. He supplied Edward VII with cigarettes. "He had a manservant who was literally a serf. Presumably my grand-father brought him from Poland. He slept on the floor at the factory. My grandfather, who had some sort of pretensions, would take him out shopping, and would point with his stick at what he wanted picked up, and Mok – that was his name – would go and pick it up and carry it home. Completely feudal. I never met my grandfather. I wish I had."

Her mother, Maude, was a professional singer of lieder and sentimental ballads, who enjoyed some success in America. She gave up her career when she married Newson Bruckner, who had also migrated from Poland to Britain, when he was 16, and had fought for the British Army in the First World War, and then been 'conscripted' into the family firm. "A devoted, virtuous and unhappy man," Brookner remembers. Why unhappy? "Because my mother was unhappy. She thought she married the wrong man. And they were loyal and devoted and all that, and both very unhappy. It took me a long time to find that out."

In life, there are no happy endings. Because the body gives you away. It lets you down. It betrays you. And you're tied to mortality. And there is no escape. Age is the final betrayal.

Anita Brookner

She was an only child, but the house was seldom empty. There were family friends and relatives –"who I didn't like much" – engaged in what she describes as 'elevated gossip. In those days women were spiteful. It was pre-feminist, and they weren't very kind to each other.' And you would sit there watching as they sliced at each other with verbal razor-blades? 'That's right.' Not a spectacle to instil you with a sense of the beneficence and kindness of humanity. 'No.' And then there were the staff – maids and cooks, all of them refugees from Germany who had been taken in by her parents, "all Jewish, as we were. And all very unhappy." She laughs. "Everybody was unhappy."

Art provided another world. 'A better world.' The Dulwich Picture Gallery was nearby, and she would spend every Sunday afternoon there. She can remember the first picture to truly move her – The Triumph of David, by Nicolas Poussin. 'I was moved by the impulse behind it. Why this picture, in this form? And why does he take the story so seriously? It was the seriousness of the conception. And the Rembrandts there – just someone looking out of the window. Amazing to capture that instant, that image. I wanted to know why and how they captured that.'

After gaining a BA in history from King's College London, she went on to gain a doctorate in art history at the Courtauld Institute of Art. Her mother did not approve of her decision to become an academic. "She thought I wouldn't get married, and that would be her disappointment." Her mother was right. But one senses that it was her mother's own disappointment – the career that she had sacrificed for an unhappy union – that was at work in Brookner's choice not to marry. She had no desire, she says, 'to be taken over' by a man. "It would have meant giving up work."

When, in 1950, she accepted a French government scholarship to study at the Ecole du Louvre in Paris, her parents, furious, cut her off. Brookner felt only liberation. Studying, writing, visiting every gallery and museum within striking distance. "I loved it. Instantly. And it occurred to me that I wasn't cut out to be a householder. I lived in a hotel, which is an ideal existence. You have no responsibilities. You eat out; you don't make your bed. You go off to work every morning – and I was completely immersed in the work." She pauses. "I've never been so happy."

She returned from Paris to teach art history, first at Reading University, and then, at the invitation of its director, Anthony Blunt (later exposed as a spy for the Soviet Union), at the Courtauld, where she was to remain until her retirement. She thinks of Blunt only with gratitude for his 'enormous kindness. And he had an integrity in his work that was unmistakable.' Some people, I say, might find that word surprising. "'Maybe. But then they didn't study with him."

Her father had forgiven her by then; she had a career, a salary, a standing. Her mother's disappointments were tempered when she fell ill and Brookner put her own life to one side to look after her. She died in 1969. Brookner was, by all accounts, a brilliant and inspirational teacher.

Dr Sarah Symmons, who is now a lecturer at the Department of Art History and Theory at the University of Essex, remembers arriving for her first tutorial with Brookner. "She had a small office at the top of the building and we went in and there was a lovely smell of scent – she always wore a very nice scent. She had the window open and she was spreading seed for the pigeons on the windowsill; she said that she wanted to stop them cooing while she gave the seminar. This was so disarming and pleasant, so different from what all the other staff at the Courtauld were like. I remember sitting there and beginning to realise that this was a unique sort of teacher – somebody who really wanted to get to know her students, who was extraordinarily good at helping you blossom, and bringing out what was really good in you."

Brookner, she remembers, was an elegant, stylish figure, always beautifully dressed. 'She was terribly thin at a time when it wasn't fashionable. We used to get very worried about her and think, is she ill? And then one day she lent a French book to one of my fellow students and he opened it up and her shopping list fell out. It just said "One small pot of Marmite" and "slimming biscuits". I remember thinking; she's not actually dying, she's quite anxious to be thin. 'In tutorials she would produce a pack of cigarettes. They were non-tipped ones, quite low-grade – I was very impressed – and she would smoke her way through quite a lot of these cigarettes in the seminar. We were all encouraged to smoke, which, again, I thought was wonderful. Now, of course, she'd probably be dismissed."

Brookner published her first novel, A Start in Life, in 1981. "I think I was getting stale as a teacher, and I knew retirement was looming," she says. (In fact, she would not retire until 1989.) "And so I tried to anticipate it. And writing seemed such an exalted profession." She pauses. "Now I'm not so sure."

In an interview with The Paris Review in 1987 she talked of how her life at the time 'seemed to be drifting in predictable channels… I thought if I could write about it I would be able to impose some structure on my experience.' She now suggests it is also a way to give structure to her life. "My real work was as a teacher and an academic, and I loved it. This is really just filling the time."

Liz Calder, who as an editor at Jonathan Cape published Brookner's first six books, remembers that when A Start in Life was first sent in by Brookner's agent, a publisher's reader recommended it should be rejected. 'She was so vehement that I thought, this sounds really interesting. And I read the first sentence: "Dr Weiss, at 40, knew that her life had been ruined by literature." I thought, well that's a damned good sentence – such an interesting sentence that I had to read on. Her books have a very page-turning quality. They're beautifully constructed. And while there aren't hugely dramatic events taking place, within the world about which she writes you get a very clear and compelling portrait of human nature.'

In A Start in Life, Weiss, a professor of French literature, travels to Paris in an attempt to escape the moral obligations that govern her life. But her hopes of finding love are dashed, and she returns to London to face the responsibility of caring for her aged parents. Thus was established the abiding Brookner themes. A central protagonist who is invariably a highly intelligent, usually emotionally reserved woman (and very occasionally man) of a certain age, in search of happiness and social acceptance; the widening gulf between expectation and fulfilment; the inevitable defection of friends and lovers; whether a safe life is preferable to a reckless one.

In Hotel du Lac the timorous, middle-aged romantic novelist Edith Hope, sent into exile by her friends for reneging on her wedding promise to dull, dependable Geoffrey, has her moral probity challenged by the suave voluptuary Philip Neville. 'One can be as pleasant or as ruthless as one wants,' Neville argues. 'If one is prepared to do the one thing one is drilled out of doing from earliest childhood – simply please oneself – there is no reason why one should ever be unhappy again.' 'Or perhaps entirely happy,' Edith replies.

In Strangers it is the tentative, introspective Sturgis who is confronted with the impulsive, carefree and monstrously self-obsessed Vicky Gardner, whose only interest in him is in what he can provide for her. The person who thinks seriously about life, Brookner's books suggest, who proceeds cautiously and conscientiously, will be punished for their virtue, end up alone and dissatisfied, while the person who takes a wholly unreflecting and rather selfish view of life pays no price for it.

"But haven't you noticed that?"

She gives an amused smile. 'Think of Tony Blair. Unrealistic. Selfish. Happy as a clam!' Didn't Plato say the unexamined life is not worth living? She gives the faintest smile. 'Plato could be wrong too. I think the unexamined life is much better. Much more comfortable.'" So you wish you had been… 'Blithe…' It rolls off her tongue, wrapped in longing. A lovely word, I say. 'It's an old-fashioned word. You don't hear it much.' So you envy the blithe? 'Oh yes.' Imagine, I say, that you have been invited to a party. Do you walk to the centre of the room, and command the party to come to you? 'Never! I lurk.' Around the margins… 'Yes.' And do you initiate conversations? 'No. I listen a lot. And finally escape.' She pauses. 'With a feeling of deliverance.' (There is a delightful story of Brookner arriving at a publishing party, lingering for a few moments with a friend before disappearing in the crush. Two minutes later the friend was surprised to see her making her way back out. 'But Anita,' the friend protested, 'you've only been here five minutes.' 'And I'm so happy that three of them were spent with you,' Brookner replied.)

The social engagement, she says, warming to the subject, always filled her with anxiety. 'I think I saw them all in terms of success and failure. Socially, I was never a star.' What then would have constituted success? 'Integration. Acceptance. Total acceptance.' So when have you felt most at ease? 'Oh, at work. At the Courtauld. Teaching. Students! Lovely people! Then I did feel integrated. I felt I was doing what I most enjoyed. I loved the company. I loved the ideas, the images. And I loved the conversation! The exchange was valuable. That was authentic. Everything else was made up.' Made up? 'Like the novels. Made up. Displacement activity.'

The recurring criticism of Brookner as a novelist is that she ploughs a narrow furrow. She is mindful of the observation. Julian Barnes remembers lunching with Brookner and asking what she was working on at the moment. 'And she said, "I've just finished a novel." There was a perfectly judged pause, then she added, "It's about a lonely woman…" And gave me a very direct glance.' 'I think one keeps on writing the same book over and over again,' she now says. That, I say, is what your critics say. 'Well, it's true.' She has always admired Freud, but has resisted any temptation to undergo psychoanalysis. 'It wasn't within my scope. And one doesn't know how intelligent the interrogator would be.' But one could see her books as a form of ongoing self-analysis (she prefers the term 'self-examination'), a relentless gnawing away at the central question of her own existence. 'I write about the things I know, the condition I know.'

And does the writing help you to come to terms with that?

'Oh no, I don't think so.' Her books have no message, she says, 'no mission statement'. She pauses. 'Although I suppose they, too, are about betrayal to a certain extent.' By this she means not only the betrayal of trust or affections within a relationship, but the larger, unavoidable betrayal of life's promise – even the betrayal of literature itself. 'It's justice that you find in literature,' she says, 'particularly in classic literature, and that is what's so satisfying. In life you are tied to the body, and that takes precedence, I think. In life, there are no happy endings.' Do you really believe that? 'Yes.' Why? 'Because the body gives you away. It lets you down. It betrays you. And you're tied to mortality. And there is no escape. Age is the final betrayal.'

Is there any way of coming to terms with that?

'No. It's a life without justice. Without a moral dimension. And you just have to navigate your way through whatever possibilities you have, and live in the here and now.' Why, then, should we be good? 'Because it's actually more rewarding than to be bad. Morally more rewarding.' So to be good is a selfish act? 'I think it's a self-interested act.'

When Brookner was shortlisted for the Booker Prize for Hotel Du Lac in 1984, Liz Calder remembers telephoning her to give her the good news. Brookner replied, 'I think I shall go out and get some shoes re-soled; that will help me keep my feet on the ground.' In fact, she took a rare mis-step. 'I thought of myself much more favourably then,' she says. Thinking she could 'promote a sort of future for myself', she took 10 years off her actual age. A 'friend' – the word is wrung out to drip with sarcasm – ratted on her to The Times. Brookner's response was utterly characteristic; she wrote, complaining of the extreme bad manners in referring to her age and pointing out that 'I am 43, and have been for the past 10 years.' She is still mortified to think of it. 'It was a moment of terrible shame, of course. A silly thing to do.' Craving the good opinion of others is the abiding tyranny. 'You can't avoid it. And everybody compromises themselves in the pursuit of that.'

Was she pleased, I ask, to win the Booker? "It was the wrong book." What would have been the right one? She reflects for a moment. "I think it was The Latecomers. I should have ended it there." (The Latecomers was published in 1988.) Why didn't you? 'More displacement activity.' She looks at me. 'It's true.' She writes in an adjacent flat, that she bought many years ago to cope with the overflow of her collection of books, and as a surrogate office. She is at her desk by 7am. She has always written in long-hand – 'I like to feel the words flowing down my arm.'

She does not own a computer. The first sentence is easy, and so is the last. What comes between is 'terrifying'. 'It is actually quite a dynamic process, and very absorbing when you're doing it. But when you've done it, you're rather disgusted.' Disgusted? 'Yes. Because it's all over, and you must do it all over again.' So no feelings of exhilaration? 'Oh no. Far from it. When it's over, it's over. I mean, I can't remember my books. I can't even remember the names. They're so finished.' I ask her about her public reputation.

She says she knows absolutely nothing about it. How attached then are you to the idea of Anita Brookner, novelist? 'Oh, not at all.' So you put your books in a bottle and throw them into the ocean, and that's it? 'That's right.' She gives a slight smile. 'Still looking for justice.' Criticism? 'Mostly ill-founded – with a sneer behind it. Take it or leave it.' Praise? 'Irrelevant. It's the process. Always the process.' She pauses. 'Actually I don't get many comments on my books. My friends don't read them.' She laughs. 'They find them depressing. I don't mind.' And it doesn't deter you from pressing on… 'Oh no. I think most writers are monomaniacs; they just go on. That's probably true of me too.'

You're very hard on yourself, I say. 'Why not?' But surely you can allow yourself a measure of pride in what you have achieved? She gives a mocking, disbelieving smile. 'Really? No, I don't think so. If I felt satisfaction I would question it. Because it would be temporary. And illusory. Clutching at something that has very little validity.' The virtue of consolation, perhaps? 'Oh there is no consolation.' She fixes me with a piercing look. 'You don't believe me, do you? But it's true.' What about love, I say. 'It's an analgesic.' But surely it is more than that? That knowing smile again. 'It's the great desire, isn't it? To find love and to keep it.' She falls silent. And I am reminded of a line from one of her books, The Rules of Engagement, where one character says of another, 'It seemed that love no longer made her happy – from which I deduced that it was the real thing.'

She regrets now that she never married. There were 'several' people she might have, she says, but it was never to come to pass. 'I'm not very interesting. I'm very inward-looking. I have no household skills. I can't cook – or rather I don't cook. I doubt that I'd be very comfortable company.' She pauses. 'And I chose the wrong people, and the wrong people chose me. So it never came about. At the time that was a cause of great sadness, certainly.'

Do you feel that life has been unfair to you? 'Not at all.' She reflects a moment. 'I think I've made a hash of it. But that's my responsibility.' What in you has led you to make a hash of it –fate, or choice? 'I'm still trying to work that out.' Do you believe some people are born lucky? 'Possibly. I'm still trying to work that out too.' Of course, Brookner is completely wrong when she says she is 'not very interesting'. She is one of the most extraordinary women I have ever met, brutally candid about her inner life, completely devoid of the consolations of self-delusion or self-pity.

A conversation with her is like walking across Siberia – it may appear bleak and forbidding, but at the same time it is shockingly, exhilaratingly bracing. There is something almost heroic in her droll resistance to any glimmer of hope. 'Well,' she says. 'One must be a realist.' It is her greatest sadness that she had no children. It is 'the great dividing line. That's why I write,' she says forcefully at one point. 'Because I have no children.' But she would not, she believes, have made a good mother. 'Too anxious,' she says, matter-of-factly. All mothers are anxious, I say, and fathers too. But you cope with it. She regards me steadily. 'I'll take your word for it.'

Have you had children in your life – friends' children? 'Oh yes.' Two words have seldom sounded so warm. Godchildren? 'No. I wish I had.' Seven years ago Brookner wrote a book called The Next Big Thing – the thing in question being death. 'I have come to believe,' the central character, Elizabeth, reflects, 'that there can be no adequate preparation for the sadness that comes at the end, the sheer regret that one's life is finished.' In Strangers, Paul Sturgis's greatest fear is that he will die alone. Brookner says that was not a prospect she had ever thought about until two years ago, when she had a spell in hospital. 'It was the first time I'd ever been in hospital, and it was so awful… literally dying among strangers. Or that was the fear.'

You were frightened? 'Who wouldn't be?' But you recovered… 'Yes. God's little joke.' When I ask if she is happy, her reply is immediate. 'No. Contented. But unfulfilled. No children.' She is lonely, she says, for 'ideal company' – which is not quite the same as being lonely. 'I'm very good on my own. And I manage, I think, pretty well. But it takes courage.' Like Sturgis she has her strategems for filling the day. She reads – 'every new novel that comes out', journalism, the newspapers. Many of her friends have died, and the writer's life, by definition solitary, means that she has never had colleagues and the particular closeness that affords. 'I depend on strangers. I want their information, you see. And it is the girl who cuts my hair, and the people I see in the street.'

She smiles. 'I'm always interrogating people. I keep asking the questions in the hope that I'll get more information. And that information will provide me with material for reflection.' In an ideal world, she would move to Paris, and live in a hotel. The perfect existence of her youth. 'But I haven't the courage now. I'm too old, and I rely on habit.' She pauses. 'A good title for a book. Creature of Habit.' But she doubts that she will write it, or indeed any other novel again. But you haven't resolved your inner search. 'No. But I'm getting bored with my characters – my character.' That suggests you are getting bored with yourself. 'Completely.' What, I ask, could anyone offer to stave off that boredom? 'But you have! Meaningful conversation. I've enjoyed this. It's been rigorous.'

The afternoon light is fading – the moment of that 'slight failure of nerve'. And what will you do now, I ask, rising to leave. 'Make a cup of tea. Go and get an evening paper. Talk to the Indian newsagent. Come home. Have a bath. Watch Channel 4 News.' She gives a slight smile. 'You're getting the detail now. Then take a sleeping pill, then bed. What time? Oh, nine.' And then tomorrow get up and do the same thing all over again? 'That's right.'